With development of technology and the Internet, servers or other equipment having large scale integrated circuits are provided with high integration density. A central processing unit (CPU) or a disk array in the server has increased processing speed, leading to greater heat accumulation in the server chassis. If the accumulated heat cannot be expelled out from the server chassis, temperature of elements or components in a system will increase continuously to cause malfunction. Even worse, the elements or components may be damaged. In order to ensure the server to operate normally, a heat dissipation fan is utilized to generate air flow and to thereby achieve heat exchange, so as to quickly expel the heat out from the server chassis. However, the key of efficient heat dissipation is to control operation of the heat dissipation fan.
In order to improve heat dissipation of the server chassis, besides having a temperature sensor in a heat source, the temperature sensor is also disposed in a proper position in the server chassis for measuring a temperature variation or difference between the heat source and the server, so that a rotation speed of the heat dissipation fan can be properly controlled, and heat dissipation efficiency of the server chassis is improved.
However, the temperature sensor in the server tends to be affected by air flow, heat conduction, or other factors, leading to an inaccurate temperature measurement. In other words, the temperature measurement is influenced by ambient temperature variations. Therefore, it is the aim of the present invention to accurately measure the temperature of the server chassis to thereby effectively control the heat dissipation efficiency.